Apparatus and method for automatically making a duplicate key

ABSTRACT

A key duplicating apparatus having automatic key clamping mechanisms for a master key and a key blank, a circular key follower and a key cutter mounted on a pivoting base that pivots and slides on a support shaft, and a mounting plate for mounting the clamping mechanisms and the support shaft. The apparatus is preferably automatically controlled by a microprocessing circuit. Also, the circular key follower is eccentrically mounted on a mounting shaft for adjustment of the depth of cutting of the key blank.

This application is a continuation-in-part of Ser. No. 541,788 filedOct. 13, 1983 now abandoned.

FIELD OF THE INVENTION

This invention relates to machines for making duplicate keys, and moreparticularly, to key duplicating machines that are automatic.

BACKGROUND OF THE INVENTION

Although attempts have been made in the past to provide automatic keyduplicating machines which are suitable for unattended use by thepublic, usually by the insertion of a coin, so far as is known none ofsuch prior coin actuated machines for making duplicate keys have beensuccessful commercially.

Examples of such prior coin operated key duplicating machines are U.S.Pat. Nos. 3,358,561; 3,442,174; and 3,796,130. The mechanisms for suchprior apparatus has been extremely complicated and adequate provisionhas not been made for assuring that the master key and the key blank areproperly indexed and clamped prior to the cutting of the duplicate key.

Most prior key duplicating machines having less complicated mechanismshave not been suitable for completely automatic operation. Ideally, acustomer would only need to insert a master key in one slot, insertmoney in another slot, and receive a duplicate key. However, most priorkey duplicating machines are designed such that the keys move during theduplicating process. As a result, these machines are not easily providedwith slots for the insertion of the keys.

A notable exception is U.S. Pat. No. 3,430,535 which describes a keyduplicating machine constructed to receive and automatically clamp amaster key and a key blank within fixed slots in the front of themachine. This convenient placement of the key slots was made possible bythe design of the key duplicating components. A key follower and keycutter are mounted with a first base that is slidably mounted on fourvertical corner posts. The corner posts are mounted with a second basethat is slidably mounted on two horizontal support shafts. Although notvery complex, this design is not the most accurate for duplicating keyssince the first base is prone to wobbling as it moves up and down on thecorner posts in response to edge variations in the master key.

The most accurate key duplicating machines generally include a base thatpivots and slides on a single support shaft. Mounted with the pivotingbase can be either the keys, as described by U.S. Pat. Nos. 3,006,255and 4,023,464, or the key follower and key cutter, as described by U.S.Pat. No. 3,675,536. As previously mentioned, key duplicating machinesthat involve movement of the keys, such as the 3,006,255 and 4,023,464patents, are not suited for completely automatic operations.Furthermore, the 3,675,536 patent, which states that the describedmachine is semi-automatic, has fixed key clamps that mount the keysparallel to the front of the machine within a safety cover. The clampscould not be repositioned for insertion of the keys into slots in themachine.

Additionally, the prior art has used key followers of a bar shape toengage edge variations in master keys. The bars are often adjustable forcontrolling the depth of cutting of the key blank to compensate forvariations in the placements of the master key and key blank.

SUMMARY OF THE INVENTION

An accurately reproduced duplicate key is made with the apparatus ofthis invention by inserting a master key and a key blank into slots inthe apparatus, properly indexing the master key and the key blank priorto clamping them automatically, and then tracing edge variations of themaster key with a key follower mounted on a pivoting base that pivotsand slides on a support shaft that is mounted perpendicular to amounting plate. A key cutter is also mounted on the pivoting base andduplicates the edge variations of the master key onto the key blank. Thekeys are clamped by key clamping mechanisms mounted on the mountingplate.

The operation of the apparatus of this invention is preferablycontrolled by a microprocessing circuit that instructs customers when toinsert the master key and the key blank and automatically operatesvarious components of the apparatus.

The apparatus preferably has key clamping mechanisms that are designedto employ low voltage solenoids to automatically clamp the keys when thekeys are properly inserted.

A circular key follower is provided which has an annular sharp edge toengage the edge variations of the master key. The key follower iseccentrically mounted on a mounting shaft so that the follower can beadjusted by simply rotating the mounting shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the mounting plate which is used to support andattach the key clamping, key indexing, and key duplicating components ofthe invention, looking at such plate from the front;

FIG. 2 is a view from the rear of the mounting plate of FIG. 1, andillustrating the arrangement of the key clamping components and the keyindexing components of the invention from that direction;

FIG. 3 is a view from the rear of the apparatus of this invention,showing the key duplicating components with the mounting platetherewith;

FIG. 4 is a view from below the key duplicating components of FIG. 3,without the mounting plate, but including components which are not shownin FIG. 3;

FIG. 5 is a view taken on line 5--5 of FIG. 1 and illustrates in detailthe master key clamping mechanism of this invention with the master keyin position for duplication;

FIG. 6 is a view taken on line 6--6 of FIG. 5 to further illustrate themaster key clamping mechanism;

FIG. 7 is a view taken on line 7--7 of FIG. 5 to further illustrate themaster key clamping mechanism;

FIG. 8 is a view taken on line 8--8 of FIG. 1 to illustrate the detailsof the mechanism for clamping the key blank;

FIG. 9 is a view taken on line 9--9 of FIG. 8 to further illustrate thedetails of the clamping mechanism for the key blank;

FIG. 9A is an enlargement of a portion of FIG. 9 to further show thedetails of the clamping mechanism for the key blank;

FIG. 10 further illustrates the details of the key indexing mechanismthat assures the proper positioning of the master key prior to theclamping of such key in the apparatus;

FIG. 10A is, a view taken on line 10A--10A of FIG. 10 to further showthe details of the key indexing mechanism for the master key;

FIG. 11 is a side view of the circular key follower of this invention;

FIG. 11A is an end view of the key follower of FIG. 11; and

FIG. 12 is a schematic electrical circuit diagram showing the electricalswitches and other components of the electrical system for operating theapparatus of this invention.

DETAILED DESCRIPTION OF A PREFERRED EMBOIDMENT OF THE INVENTION

In the drawings, the letter P designates generally a mounting plate madeof metal or other sufficiently rigid and strong material for themounting thereon of the rest of the apparatus of this invention. Theplate P has a beveled opening 10 with a slot 10a for receiving a masterkey K (FIG. 5) to be duplicated. Also, the plate P has a beveled opening12 with a slot 12a for receiving a key blank B (FIG. 8) to be cut so asto form a duplicate of the master key K.

It will be understood that the mounting plate P is supported in aconventional manner by a housing which is not shown to better illustratethe invention. The rest of the apparatus of this invention is containedwithin the housing behind the mounting plate P, thus making theinvention ideally suited for use as coin operated vending machines.Accordingly, in a preferred embodiment, the plate P has a coin slot 14for receiving coins G to actuate the apparatus of this invention, aswill be explained. A coin return slot 14a is located below the coin slot14 for rejected coins that are not of the proper denomination or areotherwise unacceptable.

The plate P also contains a test slot 15 for receiving the master key toassist the customer in deciding if the apparatus is suitable forduplicating his master key before inserting coins in the coin slot 14.

The plate P also contains a key brushing slot 16 for receiving afinished duplicate of the master key. A key brush 16a for removing burrsis mounted behind the brushing slot 16 (FIG. 2).

The plate P also contains a key dispensing slot 18 for dispensing keyblanks from a dispenser 18a (FIG. 2) after the master key is properlyindexed and clamped as described below. The dispenser 18a is of aconventional design having a slot in a sliding plate (not shown) fortransferring a single key blank from a stack of key blanks SB to the keydispensing slot 18. The dispenser 18a is mechanically operated by adispenser motor M-4 that is operably connected to the sliding plate.Alternatively, key blanks could be dispensed by a separate device foruse in the key duplicating apparatus.

The Master Key Indexing and Clamping Mechanism

The master key K is automatically indexed and clamped by insertion intothe key slot 10a. As best seen in FIGS. 5-7, a key receiving body 20 hasa generally circular portion 20a which fits against the inside of themounting plate P. An extension 20b of the body 20 extends into anopening in the plate P and provides the beveled opening 10 previouslyidentified as being in the plate P. Also, the key slot 10a is providedin the circular portion 20a of the body 20. The body 20 is attached tothe plate P by bolts or other suitable means.

A fixed clamping plate 21 is mounted with the receiving body 20, andpreferably is made of a hardened steel to resist wear. A movableclamping plate 22 is positioned adjacent the fixed clamping plate 21 andis normally spaced therefrom a predetermined distance by a spring 23bwhich is mounted in a recess 21a in the fixed plate 21. The spring 23bis held in position by a pin 23 which has an end 23a that isfrictionally held in an opening 20d of the body 20. The pin 23 isslidably located in an opening 22a of the movable clamping plate 22(FIG. 7).

A second alignment pin 24 is frictionally held in an opening 20e in thebody 20 and an opening 21b in the fixed plate 21, and is slidablylocated in an opening 22b in the movable clamping plate 22 (FIG. 6).

Axially aligned bores 20f, 21c, and 22c are provided in the keyreceiving body 20, the fixed plate 21, and the movable plate 22,respectively, to receive the shaft of a bolt 25, which is slidablymounted therein. The bolt 25 has one end 25a connected by a retainingpin 26 to a clevis end 27a of a solenoid actuated operating arm 27. Theclevis end 27a of the arm 27 acts as a cam to move the movable plate 22when the arm 27 is rotated. The arm 27 is connected by a pivotallyattached link 28 and a pivot pin 28a to a low voltage solenoid S-1 (FIG.2). The other end of the bolt 25 has a pair of nuts 25b for locking thebolt in a selected position to accomplish the clamping of the master keyK between the fixed clamping plate 21 and the movable clamping plate 22when the arm 27 cams the movable plate 22. To receive the master key Kbetween the fixed plate 21 and the movable plate 22, the fixed plate 21has a recess 21d and the movable plate 22 has a corresponding recess 22d(FIG. 6.).

Turning now to FIGS. 2, 10 and 10A, to be certain that the master key Kis positioned both horizontally and vertically very accurately prior tothe clamping of the master key K between the fixed plate 21 and themovable plate 22, an indexing mechanism is provided. Such indexingmechanism includes a switch SW-3 which is a conventional microswitchhaving a contact strip 29 which is mounted to be engaged by an edge K"of the master key K as best seen in FIG. 5. In addition, an indexingmember 30 holds a positioning finger 32 against the edge variations ofthe master key K to ensure that the edge K" of the key K engages thecontact strip 29 when the key K is inserted (FIG. 10).

The indexing member 30 is pivotally connected at 30b to a pivot block 31by a pivot pin 35 that is frictionally mounted in a recess 31a in thepivot block 31. The member 30 is also pivotally connected at 30a to amechanism for pivoting the indexing member 30 such that the indexingmember 30 and positioning finger 32 can be moved away from the masterkey K. As best shown in FIG. 2, the mechanism for pivoting the indexingmember 30 includes an electric motor M-3 that is connected to a gearbox34. The gearbox 34 drives a push member 33 that is attached to theindexing member 30 at 30a.

When the master key K is inserted into the slot 10a, a shoulder K' ofthe key K engages the indexing member 30 causing movement of the member30 in a direction away from the plate P (FIG. 10). Such movementovercomes the action of a spring 36 that is mounted in a recess 31b inthe pivot block 31. The spring 36 normally holds the member 30 adjacentthe rear surface of the mounting plate P. Movement of the indexingmember 30 by the shoulder K' is stopped by a surface 31c of the pivotblock 31 at a point where the indexing member 30 engages a contact strip37 of a second switch SW-7. The strip 37 is positioned to engage themember 30 only if the member 30 is in a lowered position to engage theshoulder K' of the master key K. When the indexing member 30 ispositioned to engage the shoulder K', the positioning finger 32 alsoengages the key K to ensure that the edge K" of the key K engages thecontact strip 29 of the first switch SW-3. The engagement of switchesSW-3 and SW-7 as described above activates the solenoid S-1 for clampingthe master key K when the edge K" and the shoulder K' of the master keyK are positioned properly within the clamping mechanism.

Key Blank Clamping Mechanism

FIGS. 2, 8 and 9 illustrate the details of the key blank clampingmechanism of this invention. The mounting plate P receives a key blankreceiving body 40 that has a circular portion 40a and a portion 40bwhich extends into the plate P to provide the beveled surface 12. Afixed clamping plate 46 is mounted with the receiving body 40, andpreferably is made of a hardened steel to resist wear.

A movable clamping plate 41 is positioned adjacent the fixed plate 48and is resiliently urged away from the fixed plate 48 by a spring (notshown) which is similar to the master key clamp spring 23b. The springis held in place by a pin 49 that is mounted similar to the pin 23 forholding the master key clamp spring 23b. A guide pin 43 is frictionallysecured in an opening 40d of the body 40 and an opening 48a of the fixedplate 48, and slidably fits in an opening 41a of the moveable clampingplate 41.

A bolt 42 loosely extends through axially aligned bores 40c, 48b, and41b in the body 40, the fixed plate 48, and the movable plate 41,respectively. The clamping plate 41 is moved by a clevis end 44a of anactuating arm 44 into which one end 42a of the bolt 42 extends and isattached by a pivot pin 45. Nuts 42b are used to position and secure thebolt 42 in the desired relationship for proper clamping of the movableplate 41. The actuating arm 44 is connected by a pivotally attached link46 and a pivot pin 46a to a low voltage solenoid S-3. To facilitate theclamping of the blank B between the fixed plate 48 and the movable plate41, the fixed plate 48 has a recess 48c, and the movable plate 41 has acorresponding recess 41c.

The key blank B is indexed by a spline 41d on the moveable plate 41 thatfits a groove B' in the key blank B, and by a spline 48d on the fixedclamping plate 48 that fits a second groove B" in the key blank B. Thesplines 41d and 48d function to replace the positioning finger 32 usedfor the master key clamping mechanism. The head of the key blank B actsas a stop by engaging the outer surface 40e of the circular portion 40aof the body 40. Thus, the outer surface 40e functions to replace theindexing member 30 used for the master key clamping mechanism. A singleswitch SW-5 is positioned to engage the tip of the key blank B with acontact strip 47 when the key blank B is fully inserted. The switch SW-5activates the solenoid S-3 for clamping the key blank B when the keyblank is positioned properly in the key clamping mechanism.

Key Follower and Cutter Mechanisms

FIGS. 3 and 4 illustrate the details of the key duplicating components.Such components are mounted on a support shaft 60 which is substantiallyperpendicular to the mounting plate P and connected to the plate P byany suitable means. An electrical transport motor M-1 operates a gearbox 62 that is mounted on a base 61. The base 61 is in turn secured tothe shaft 60 by a plurality of set screws 61a. The gearbox 62 and motorM-1 drives a key follower mechanism and a key cutter mechanism asdescribed more fully below.

A pivoting base 65 having a bore or opening 65a is mounted on the shaft60 such that the base 65 can pivot and slide relative to the shaft 60. Akey cutter motor M-2 is mounted on the pivoting base 65 so that themotor M-2 and the base 65 can pivot together. The motor M-2 is connectedby a drive belt 66 or any other suitable drive means to a shaft 67 whichrotatably extends through an opening 65b in the base 65. The shaft 67mounts a key cutter 68 at the forward end of the base 65. The key cutter68 is positioned adjacent the key blank B when the key blank B isclamped between the movable clamping plate 41 and the fixed clampingplate 48.

A key follower 70 of circular shape and having a sharp annular edge 70ais eccentrically mounted on a mounting shaft 71. The mounting shaft 71is secured to a block 72 that is mounted on the pivoting base 65 suchthat the key follower 70 is positioned adjacent the master key K whenthe key K is clamped between the movable plate 22 and the fixed plate21. Movement of the key follower 70 in response to the edge variationsof the master key K cause the pivoting base 65 to pivot on the shaft 60.Such movements are simultaneously transmitted to the key cutter 68 so asto cut edge variations in the key blank B which are identical to theedge variations in the master key K. The key follower 70 iseccentrically mounted on the shaft 71 (FIGS. 11 and 11A) to allowadjustment of the depth of the cutting of the key blank B by rotatingthe shaft 71.

The transport motor M-1 is connected to the gear box 62 for transportingthe pivoting base 65, together with the cutter motor M-2, the cutter 68,and the key follower 70, in a reciprocating longitudinal movement on theshaft 60 during the cutting of the key blank B. As shown in FIG. 4, anoutput shaft 62a from the gearbox 62 is connected to a rotor 81 thatrotates in a recess 80 in the base 61. A linkage 83 extends from therotor 81 to the pivoting base 65. Suitable universal joints 82 areprovided at each end of the linkage 83 and connect the linkage 83 to therotor 81 at 85 and to the pivoting base 65 at 84. As the rotor 81rotates, the linkage 83 causes reciprocation of the pivoting base 65 onthe shaft 60 between a ready position away from the mounting plate P anda finished position near the plate P. Such movement causes the keyfollower 70 to trace the master key K, and also causes the key cutter 68to cut the key blank B to form a duplicate of the master key K.

The weight of the pivoting base 65 and the other components mountedtherewith are counterbalanced so that at least a portion of such weightis applied by gravity to the key follower 70 to maintain a uniformpressure on the master key K. The weight applied to the master key K maybe adjusted by repositioning the cutter motor M-2 on the base 65 so thatsufficient weight is applied through the key follower 70 to maintaincontact with the edge variations of the master key K, but withoutexerting excessive weight on the key K so as to interfere with movementof the key follower 70.

Springs (not shown) are preferably use to help hold the key follower 70in contact with the master key K and can be mounted in any manner thatbiases the key follower 70 toward the master key K. Without the use ofsprings, the key follower 70 might glide over some edge variations dueto the inertia of the pivoting base 65 and other components mounted withthe pivoting base 65.

Electrical Circuit and Operation

FIG. 12 is an electrical diagram illustrating the preferred circuit forthe operation of the apparatus of this invention. Electrical power issupplied through any conventional 110 volt AC source at the supplyterminals 90a and 90b. A master switch SW-1 of conventional constructionis provided in the line from the 110 volt alternating current supply andis adapted to be closed by an operator or a timer of known construction.After the switch SW-1 is closed, power is supplied to a transformer 92and is converted to 24 volts alternating current which passes through aconventional electrical diode bridge 94 to provide 24 volts directcurrent.

The circuit includes a microprocessing circuit 96 that receives inputfrom various switches mounted on the apparatus and leads a customerthrough the operation of the apparatus by a series of lights (not shown)or similar means. The switches are connected to the microprocessor 96through conventional input switch circuitry 95 which conditions theswitch signals for input to the microprocessor 96. The various solenoidsand motors of the apparatus are connected to the microprocessor 96 byconventional solenoid driver circuitry 97 and motor driver circuitry 98which conditions the signals from the microprocessor 96 for operatingthe solenoids and motors.

When the apparatus is ready to duplicate a master key K, a switch SW-4informs the microprocessor 96 that the pivoting base 65 is in the readyposition and a switch SW-6 informs the microprocessor 96 that theindexing member 30 is in a raised position. The microprocessor thensignals potential customers by lights that the apparatus is ready toautomatically duplicate a key. The customer is instructed to insert hismaster key K into the test slot 15. If the inserted key can beduplicated, the key K engages a switch SW-10 that informs themicroprocessor 96 that the test is successful. The microprocessor 96then operates the motor M-3 for pivoting the indexing member 30 until aswitch SW-8 informs the microprocessor 96 that the indexing member 30has moved to the lowered position. The customer is then instructed by alight to insert the master key K into the next slot 10a. A second switch(not shown) is preferably mounted with the test slot 15 to engage keysthat fit the slot 15 and engage the first switch SW-10, but are too longfor the available key blanks B. The engagement of this switch by themaster key K informs the microprocessor 96 that the test is notsuccessful and the customer is so instructed by a light.

The master key K must be properly inserted in the master key slot 10awithin a specified time or else the microprocessor 96 automaticallyreturns the indexing member 30 to the raised position and signalscustomers that the apparatus is ready to duplicate a key. Properinsertion of the master key K is achieved by the engagement of theindexing switches SW-3 and SW-7 as previously described. The engagementof both switches SW-3 and SW-7 causes the microprocessor 96 to operatethe master key clamping solenoid S-1 to clamp the master key K. Themicroprocessor 96 then instructs the customer by a light to insert coinsinto the coin slot 14.

The proper insertion of coins G into the coin slot 14 engages a coinswitch SW-2 which informs the microprocessor 96 to operate thedispensing motor M-4 to dispense a key blank B from the key dispensingslot 18. Alternatively, the insertion of the coins would provide thecustomer with the key blank B by any other means such as activation of aseparate key dispenser. A switch SW-9 informs the microprocessor 96 whena key blank B has been dispensed and the microprocessor 96 theninstructs the customer by a light to insert the key blank B into thenext key slot 12a. A failure to properly insert coins or any failure tocomplete the rest of the operation causes the microprocessor 96 torelease the master key K.

The insertion of the key blank B into the slot 12a engages the indexingswitch SW-5 as previously described and causes the microprocessor 96 tooperate the key blank clamping solenoid S-3 to clamp the key blank B.The microprocessor 96 then automatically operates the motor M-3 forraising the indexing member 30 until the switch SW-6 informs themicroprocessor 96 that the indexing member 30 is in the raised position.The microprocessor 96 then automatically operates the key cutter motorM-2 and the transport motor M-1 causing the key follower 70 to trace theedge variations of the master key K and the key cutter 68 to cutduplicate variations in the key blank B, as previously described.

The cutting of the key blank B is completed within one revolution of therotor 81 that is turned by the transport motor M-1. The revolutioncauses the pivoting base 65 to move the key follower 70 and the keycutter 68 from the ready position to the finished position near themounting plate P and then return to the ready position. The return ofthe pivoting base 65 to the ready position engages the switch SW-4 thatinforms the microprocessor 96 that the pivoting base 65 is in the readyposition, and causes the microprocessor 96 to shut-off the cutter motorM-2 and the transport motor M-1. The microprocessor 96 thenautomatically shuts-off the power to the key clamping solenoids S-1 andS-3 causing the key clamping mechanisms to release the master key K andthe key blank B which has become a finished duplicate key. The solenoidsreturn to their unclamped positions by the usual internal springs.

When the key clamping mechanisms release the keys, the microprocessor 96instructs the customer by a light to remove the keys. The removal of themaster key K and the duplicate key disengages the indexing switchesSW-3, SW-7, and SW-5 which informs the microprocessor 96 to instruct thecustomer by a light to insert the duplicate key into the key brushingslot 16 for removal of any burrs with the key brush 16a. The key brush16a operates whenever a key is inserted. After a brief period of time,the microprocessor 96 automatically returns to the beginning of thedescribed sequence of operation and signals customers by the lights thatthe apparatus is ready to duplicate a key.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

What is claimed is:
 1. A method for making a duplicate key, comprisingthe steps of:instructing a customer to insert a master key into firstkey clamping means; automatically clamping the master key when themaster key is properly indexed within the first key clamping means;automatically dispensing a key blank from dispensing means after themaster key is clamped; instructing the customer to insert the key blankinto second key clamping means; automatically clamping the key blankwhen the key blank is properly indexed within the second key clampingmeans; automatically tracing the master key with key following meansafter both the master key and the key blank are clamped; cutting the keyblank with key cutting means operably connected to the key followingmeans to form a duplicate of the master key; and automatically releasingthe master key and the duplicate of the master key after the keyfollowing means has completed the trace of the master key.
 2. The methodof claim 1, wherein the key cutting means is operably connected to thekey following means by mounting both the cutting means and the followingmeans on a pivoting base that pivots and slides on a support shaft thatis perpendicular to a mounting plate which mounts the support shaft andboth key clamping means.
 3. An apparatus for duplicating a key,comprising:means for instructing a customer to insert a master key intoa first key slot; first key clamping means for automatically clampingthe master key when the master key is properly indexed within the firstkey slot; key dispensing means for automatically dispensing a key blankafter the master key is clamped1 means for instructing the customer toinsert the key blank into a second key slot; second key clamping meansfor automatically clamping the key blank when the key blank is properlyindexed within the second key slot; key following means forautomatically tracing the master key after both the master key and thekey blank are clamped; key cutting means for cutting the key blankduring the tracing of the master key to form a duplicate of the masterkey; and means for automatically releasing the master key and theduplicate of the master key after the tracing of the master key iscompleted.
 4. The apparatus of claim 3, wherein the key cutting means isoperably connected to the key following means by mounting both thecutting means and the following means on a pivoting base that pivots andslides on a support shaft that is perpendicular to a mounting platewhich mounts the support shaft and both key clamping means.